From 5c7e3d16382de2fd720bd498edffee301ac4a9c5 Mon Sep 17 00:00:00 2001
From: Haley Glavina <HaleyGlavina@Haleys-MacBook-Pro.local>
Date: Tue, 27 Feb 2018 17:04:37 -0500
Subject: [PATCH] Haley and Lawrence worked on Mergesort
---
src/sandbox/GeneralCompare.java | 5 ++-
src/sort/GeneralCompare.java | 4 +-
src/sort/MergeSort.java | 68 ++++++++++++++++++++++-----------
3 files changed, 50 insertions(+), 27 deletions(-)
diff --git a/src/sandbox/GeneralCompare.java b/src/sandbox/GeneralCompare.java
index 29332aa..9e7584c 100644
--- a/src/sandbox/GeneralCompare.java
+++ b/src/sandbox/GeneralCompare.java
@@ -1,5 +1,6 @@
package sandbox;
-public interface GeneralCompare<T> {
- public int eval(T a1, T a2);
+public interface GeneralCompare {
+ public int eval(Comparable a1, Comparable a2);
+
}
diff --git a/src/sort/GeneralCompare.java b/src/sort/GeneralCompare.java
index 76bf31f..b5d51af 100644
--- a/src/sort/GeneralCompare.java
+++ b/src/sort/GeneralCompare.java
@@ -1,5 +1,5 @@
package sort;
-public interface GeneralCompare<T> {
- public int compare(T a1, T a2);
+public interface GeneralCompare {
+ public int compare(Comparable a1, Comparable a2);
}
diff --git a/src/sort/MergeSort.java b/src/sort/MergeSort.java
index b3c7db4..591ee8c 100644
--- a/src/sort/MergeSort.java
+++ b/src/sort/MergeSort.java
@@ -1,35 +1,59 @@
package sort;
+import java.lang.reflect.Array;
+
public class MergeSort{
-
+
private static Comparable[] aux;
- public static void merge(Comparable[] x, int lo, int hi, GeneralCompare gc){
+ public static void main(String[] args) {
+ GeneralCompare b1;
+ b1 = (a1, a2) -> (Integer) a1 - (Integer) a2;
+ Integer[] test = {3, 4, 2, 1, 5, 7, 9, 10};
+ sort(test, 0, Array.getLength(test) - 1, b1);
- int n = hi - lo;
- aux = new Comparable[n];
+ for (int i = 0 ; i < (Array.getLength(test) - 1) ; i++) {
+ System.out.println(test[i]);
+ }
+ }
+ public static void sort(Comparable[] x, int lo, int hi, GeneralCompare gc) {
+ aux = new Comparable[Array.getLength(x)];
+ sortWrapped(x, 0, Array.getLength(x) - 1, gc);
+ }
+
+ private static void sortWrapped(Comparable[] x, int lo, int hi, GeneralCompare gc) {
+ int n = hi - lo;
if(n <= 1)
return;
- // Recursively merge each half of the array
- int mid = (n/2) + 1;
- merge(x, lo, mid, gc);
- merge(x, mid+1, hi, gc);
-
+ // Recursively sort each half of the array
+ int mid = lo + (n/2);
+ sortWrapped(x, lo, mid, gc);
+ sortWrapped(x, mid+1, hi, gc);
+ merge(x, lo, hi, gc);
+ }
+
+ private static void merge(Comparable[] x, int lo, int hi, GeneralCompare gc){
+
+ int n = hi - lo;
+ int mid = lo + (n/2);
+
// Fill auxiliary array
- for(int k = 1; k <= n; k++){
+ System.out.println(n);
+ for(int k = lo; k <= hi; k++){
aux[k] = x[k];
}
-
- //
- while ((mid < hi) | (lo < mid)) {
- if (compare(aux[lo], aux[mid]))
- x[lo++] = mid;
-
+
+ int i = 0;
+ // Merging two sorted arrays
+ while ((lo <= mid) & (mid <= hi)) {
+ if (gc.compare(aux[lo], aux[mid]) > 0)
+ x[i++] = aux[mid++];
+ else
+ x[i++] = aux[lo++];
}
-
-
-
+
+ /*
// Is this portion sorting the aux array? Check
for(int k = 1; k <= n; k++){
if(i > j-1)
@@ -40,9 +64,7 @@ public class MergeSort{
x[k] = aux[j++];
else
x[k] = aux[i++];
- }
-
- }
-
+ }*/
+ }
}
--
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